DSpace Community:http://hdl.handle.net/10261/5063
Sun, 02 Aug 2015 20:27:28 GMT2015-08-02T20:27:28ZDSpace Community:http://digital.csic.es:80/retrieve/56718/iqac.jpghttp://hdl.handle.net/10261/5063
Electrophysiological and behavioural responses of Pityophthorus pubescens (Coleoptera: Scolytinae) to (E,E)-alpha-farnesene, (R)-(+)-limonene and (S)-(-)-verbenone in Pinus radiata (Pinaceae) stands in northern Spainhttp://hdl.handle.net/10261/116179
Título : Electrophysiological and behavioural responses of Pityophthorus pubescens (Coleoptera: Scolytinae) to (E,E)-alpha-farnesene, (R)-(+)-limonene and (S)-(-)-verbenone in Pinus radiata (Pinaceae) stands in northern Spain
Autor : Lopez, Sergio; Quero, Carme; Iturrondobeitia, Juan Carlos; Goldarazena, Arturo; Guerrero, Angel
Resumen: Some twig beetles in the genus Pityophthorus (Coleoptera: Scolytinae) may vector pitch canker disease Fusarium circinatum (Niremberg & O'Donnell) of Pinus spp. (Pinaceae). Because Pityophthorus pubescens (Marsh.) has been found to be associated with F. circinatum in the Basque Country (northern Spain), various experiments were conducted to assess the beetle's behavioural responses to (E, E)-alpha-farnesene, (R)-(+)-limonene and (S)-(-)-verbenone to develop a potential inhibitor to host attraction. These experiments comprise electroantennographic and double-choice olfactometer tests, as well as field assays in Pinus radiata D. Don stands. RESULTS: Both sexes of P. pubescens showed similar electroantennographic responses to different doses (from 1 ng to 1 mu g in decadic steps) of each individual compound, with depolarisations to (S)-(-)-verbenone (100 ng) being similar to those of the aggregation pheromone (+)-trans-pityol. In olfactometer assays, both sexes were significantly attracted to (+)-trans-pityol, but the attraction was reduced when increasing amounts of the chemicals were added to the pheromone. Particularly relevant was the repellent effect induced by (S)-(-)-verbenone at 1 ng dose and higher. In the field, (E, E)-alpha-farnesene, (R)-(+)-limonene and (S)-(-)-verbenone reduced significantly the number of beetles attracted to (+)-trans-pityol and racemic trans-pityol, with (S)-(-)-verbenone being the most effective. CONCLUSIONS: (S)-(-)-Verbenone showed an interesting potential for use in the protection of P. radiata stands. A potentially effective strategy, which could be implemented in further, more in-depth studies, could involve the use of this semiochemical as repellent and (+)-trans-pityol-baited traps as attractant in a push-pull strategy. Copyright (c) 2012 Society of Chemical IndustryThu, 04 Jun 2015 09:32:38 GMThttp://hdl.handle.net/10261/1161792015-06-04T09:32:38ZA Tetraene Aldehyde as the Major Sex Pheromone Component of the Promethea Moth (Callosamia promethea (Drury))http://hdl.handle.net/10261/116177
Título : A Tetraene Aldehyde as the Major Sex Pheromone Component of the Promethea Moth (Callosamia promethea (Drury))
Autor : Gago, Rafael; Allison, Jeremy D.; McElfresh, J. Stephen; Haynes, Kenneth F.; McKenney, Jessica; Guerrero, Angel; Millar, Jocelyn G.
Resumen: The promethea moth Callosamia promethea is one of three species of silkmoths from the genus Callosamia that occur in North America. Cross attraction of males to heterospecific calling females has been observed in the field, and hybrid progeny have been produced by pairing heterospecifics in captivity. These observations suggest that all three species share or have considerable overlap in the sex attractant pheromones produced by females, so that other prezygotic isolating mechanisms, such as diel differences in reproductive activity, limit hybridization in the field. Coupled gas chromatography-electroantennogram detection and gas chromatography- mass-spectrometry analyses of extracts of volatiles collected from female promethea moths supported the identification of (4E,6E,11Z,13Z)-hexadeca-4,6,11,13-tetraenal [(4E,6E,11Z,13Z)-16:Ald] as the compound in extracts that elicited the largest responses from antennae of males. The identification was confirmed by non-selective synthesis of several isomers as analytical standards, and stereoselective synthesis of (4E,6E,11Z,13Z)-16:Ald for testing in field trials. Male moths were strongly attracted to synthetic (4E,6E,11Z,13Z)-16:Ald, suggesting that this compound is the major and possibly the only component of the sex pheromone of these large saturniid moths. Based on the cross-attraction of heterospecifics, it is likely that this is also a major pheromone component of the other two North American Callosamia species as well.Thu, 04 Jun 2015 08:58:51 GMThttp://hdl.handle.net/10261/1161772015-06-04T08:58:51ZElectrophysiological and Behavioral Responses of the Black-Banded Oak Borer, Coroebus florentinus, to Conspecific and Host-Plant Volatiles.http://hdl.handle.net/10261/116174
Título : Electrophysiological and Behavioral Responses of the Black-Banded Oak Borer, Coroebus florentinus, to Conspecific and Host-Plant Volatiles.
Autor : Fuerstenau, Benjamín; Rosell, Glòria; Guerrero, Angel; Quero, Carme
Resumen: Aspects of the chemical ecology of the black-banded oak borer, (BBOB) Coroebus florentinus (Coleoptera: Buprestidae), were studied. Odors produced by males and females were similar, both qualitatively and quantitatively. Nonanal, decanal, and geranylacetone, identified in the headspace of both sexes, elicited strong electroantennographic responses from male antennae, but not from female antennae. In dual-choice olfactometer experiments, a blend of these three compounds was attractive to both sexes; males responded to decanal alone, while females responded to geranylacetone alone, suggesting that these compounds are responsible for activity of the blend to the respective sexes. Antennae of both sexes responded electroantennographically to the green leaf volatiles (E)-2-hexenal, (E)-2-hexenol, 1-hexanol, (Z)-3-hexenyl acetate, and n-hexyl acetate, all identified from the host plant Quercus suber. In behavioral experiments, only females were attracted to host-plant odors, and in tests with synthetic compounds, females were attracted to (E)-2-hexenol, 1-hexanol, and (Z)-3-hexenyl acetate. It is likely that these compounds play a role in foraging and/or oviposition behavior of BBOB females.Thu, 04 Jun 2015 08:23:20 GMThttp://hdl.handle.net/10261/1161742015-06-04T08:23:20ZElectrophilic derivatives antagonise pheromone attraction in cydia pomonellahttp://hdl.handle.net/10261/116171
Título : Electrophilic derivatives antagonise pheromone attraction in cydia pomonella
Autor : Sans, Albert; Gago, Rafael; Mingot, Ares; García, Wanda; Bosch, Dolors; Coll, Josep C.; Rosell, Glòria; Bosch, María Pilar; Riba, Magí V.; Guerrero, Angel
Resumen: Pheromone antagonists are good disruptants of the pheromone communication in insects as such, have been used in mating disruption experiments. In this study, new non-fluorinated electrophilic keto derivatives structurally related to the pheromone of Cydia pomonella (codlemone) have been synthesised and tested as putative pheromone antagonists. RESULTS: Codlemone (1) was prepared in excellent stereoselectivity in a new, iterative approach involving two Horner-Wadsworth-Emmons reactions. Methyl ketone (2), keto ester (3) and diketone (4) were obtained from codlemone in straightforward approaches in good overall yields and excellent stereochemical purity (≥98% E,E). In electrophysiology, only compound 2 displayed inhibition of the antennal response to the pheromone after presaturation of the antennal receptors. Compounds 2 to 4 did not inhibit the pheromone-degrading enzyme responsible for codlemone metabolism, but mixtures of ketone 2 and diketone 4 with codlemone elicited erratic flights on males in a wind tunnel. In the field, blends of either compound (2 or 4) with the pheromone caught significantly fewer males than codlemone alone. CONCLUSION: Codlemone and the potential antagonists 2 to 4 have been synthesised in good yields and excellent stereoselectivity. These chemicals behave as pheromone antagonists of the codling moth both in the laboratory and in the field.Thu, 04 Jun 2015 07:45:44 GMThttp://hdl.handle.net/10261/1161712015-06-04T07:45:44Z